Re: Laser Cooling

From: Everitt Mickey (evmick@pnv.net)
Date: Sun Jul 30 2000 - 01:08:27 MDT


Got it...laser cooling is just molecular speed bumps.
-----Original Message-----
From: Michael M. Butler <butler@comp-lib.org>
To: extropians@extropy.org <extropians@extropy.org>
Date: Sunday, July 30, 2000 1:44 AM
Subject: Re: Laser Cooling

>I think Mr. Lorrey misspoke. What's "evaporating" in laser cooling is
>photons, mostly. One could make a swamp cooler using a laser, and
>something very like that can be done profitably in the case of laser
>enrichment of U and Pu, but I don't believe it is what microKelvin
>researchers mean when they talk about laser cooling.
>
>I believe that the description below is pretty close to right, apart
>from the use of the word "orientated" (ish!).
>
>See
>http://homepages.strath.ac.uk/~acp96102/Research/Laser_cooling/How/How.htm
>for more details on the theory.
>
>Quoting from there: "At a very basic level 3 intersecting orthogonal
>pairs of counter-propagating laser beams of equal intensity and
>frequency, tuned slightly below the chosen atomic transition, are
>transmitted into the center of a vapour cell. The absorption of the
>photons from this transition slow down the atoms by imparting momentum
>against the direction of motion of the atom; the emission is orientated
>in a random direction. Over many cycles the velocity and thus the
>temperature of these atoms falls to a fraction above absolute zero. "
>
>Everitt Mickey wrote:
>>
>> >AND?????? What are you thinking (assuming that IS what is going on)? ;)
>> >
>>
>> In my own humble fashion...yes.
>>
>> >Lasers cool by evaporating a part of a substance, the evaporation
>> >causing the heat of the substance to drop.
>> >
>>
>> Bummer.....I didn't realize that.
>>
>> So laser cooling is just a high tech swamp cooler huh?
>>
>> I was dreaming of a laser beam to space offloading excess Btu's into the
>> void....
>>
>> Rats....
>>
>> -----Original Message-----
>> From: Michael S. Lorrey <retroman@turbont.net>
>> To: extropians@extropy.org <extropians@extropy.org>
>> Date: Sunday, July 30, 2000 12:30 AM
>> Subject: Re: Laser Cooling
>>
>> >Everitt Mickey wrote:
>> >>
>> >> I've heard the term "laser cooling" used....in fact I think that is
how a
>> >> "Bose Condescant" is generated.
>> >>
>> >> That being the case then it appears that somehow lasers are used as a
>> heat
>> >> pipe.....
>> >>
>> >> I've also heard of OTEC's....(Ocean Thermal something or
>> another)....where
>> >> electrical energy is supposed to be generated via tempeture
differential
>> of
>> >> surface vs deep sea.
>> >>
>> >> Not that I'm thinking that lasers would be much use in that
regard...but
>> it
>> >> got me to thinking........
>> >>
>> >> Four Degrees Kelvin.
>> >>
>> >> Laser Cooling.....
>> >>
>> >> ????????????
>> >
>> >AND?????? What are you thinking (assuming that IS what is going on)? ;)
>> >
>> >Lasers cool by evaporating a part of a substance, the evaporation
>> >causing the heat of the substance to drop.
>> >
>> >OTEC: Ocean Thermal Energy Conversion systems are electricity generators
>> >and water purifiers that use either closed or open Carnot cycle heat
>> >engines to transfer heat from surface water to cold water that is pumped
>> >up from the depths. Hawaii has a few installations, and there are others
>> >on islands around the world where sources of water and energy are useful
>> >when neither is in abundant supply locally from more conventional
>> >sources.
>> >
>> >A Carnot engine is a rather interesting device, to be sure, and a quick
>> >read on them is recommended.
>> >
>



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